A transceiver detecting bus activity and an ECU completing its own start-up are separate events. A wake indication does not prove every module function is ready.

What to check next

For a controller that wakes but remains unavailable, review the supply sequence, reset behaviour and supported diagnostic response. Keep these observations separate from the incoming network activity. This is particularly useful after an interrupted repair or a component substitution.

Useful information for an enquiry

Save the timing relationship between wake request, current draw and the first successful or failed diagnostic response.

The exact wake and start-up design varies. Avoid replacing the transceiver simply because the final application did not become available.

Speak to AXION

For CAN-bus and vehicle-network diagnostics, send your vehicle details and fault report. Workshop assessment is in Didcot, Oxfordshire. Suitable postal or remote work is confirmed before booking.

Technical background from NXP. The referenced design explains the principle; the vehicle-specific procedure determines the repair.